This invention relates to a grid system for a suspended ceiling and in particular to a grid system having the grid elements with raceways in which wires can be carried.
Suspended ceilings which support equipment are common in many types of commercial buildings. Clean rooms used in chip manufacture and hospitals use ceilings to support fan filter units, lights and other equipment. This equipment has wiring that provides power (high voltage wiring) and control systems (low voltage wiring). This wiring is located above the ceiling and is typically placed in raceways to protect the wire and keep it contained. Separate raceways typically are used for the high voltage and low voltage wiring.
The equipment is located throughout the ceiling so the raceways must run both longitudinally and laterally. As a result, the raceways utilize considerable space above the ceiling preventing this space from being fully utilized to contain other components and making it difficult for workers maintaining the equipment mounted in the ceiling from working in the space. In addition, since the raceways and wiring must be installed on site, after the ceiling system is installed, the installation of the wiring is expensive and the overall time necessary for constructing the space is increased. In addition, the wiring is easily disturbed by technicians working in the space.
Prior art ceiling grid systems have included raceways in the ceiling grid elements to decrease the amount of clutter and keep the wire better organized. These grid elements include a single raceway and the raceways have been located at the bottom of the grid elements. As a result the raceways cannot carry both high and low voltage wire and they must be accessed from below the ceiling. Thus, separate raceways must still be placed above the suspended ceiling and at least a portion of the wiring must be installed on site after the ceiling system is in place. As a result, the prior art ceiling grid systems do not completely solve the foregoing wiring problems with suspended ceiling systems of this type.